Treating diabetes by changing a cell’s identity. Stem cells are an ideal therapy strategy for treating type 1 diabetes. That’s because the disease is caused by the loss of a very specific cell type: the insulin-producing beta cell in the pancreas. So, several groups are developing treatments that aim to replace the lost cells by transplanting stem cell-derived beta cells grown in the lab. In fact, Viacyte is applying this approach in an ongoing CIRM-funded clinical trial.
In preliminary animal studies published late last week, a Stanford research team has shown another approach may be possible which generates beta cells inside the body instead of relying on cells grown in a petri dish. The CIRM-funded Cell Metabolism report focused on alpha cells, another cell type in pancreas which produces the hormone glucagon.
Microscopy of islet cells, round clusters of cells found in the pancreas. The brown stained cells are glucagon-producing alpha cells. Credit: Wikimedia Commons
After eating a meal, insulin is critical for getting blood sugar into your cells for their energy needs. But glucagon is needed to release stored up sugar, or glucose, into your blood when you haven’t eaten for a while. The research team, blocked two genes in mice that are critical for maintaining an alpha cell state. Seven weeks after inhibiting the activity of these genes, the researchers saw that many alpha cells had converted to beta cells, a process called direct reprogramming.
Does the same thing happen in humans? A study of cadaver donors who had been recently diagnosed with diabetes before their death suggests the answer is yes. An analysis of pancreatic tissue samples showed cells that produced both insulin and glucagon, and appeared to be in the process of converting from beta to alpha cells. Further genetic tests showed that diabetes donor cells had lost activity in the two genes that were blocked in the mouse studies.
It turns out that there’s naturally an excess of alpha cells so, as team lead Seung Kim mentioned in a press release, this strategy could pan out:
Seung Kim. Credit: Steve Fisch, Stanford University
“This indicates that it might be possible to use targeted methods to block these genes or the signals controlling them in the pancreatic islets of people with diabetes to enhance the proportion of alpha cells that convert into beta cells.”
Using computers to predict cell fate. Deep learning is a cutting-edge area of computer science that uses computer algorithms to perform tasks that border on artificial intelligence. From beating humans in a game of Go to self-driving car technology, deep learning has an exciting range of applications. Now, scientists at Helmholtz Zentrum München in Germany have used deep learning to predict the fate of cells.
Using deep learning, computers can predict the fate of these blood stem cells.
Credit: Helmholtz Zentrum München.
The study, published this week in Nature Methods, focused on blood stem cells also called hematopoietic stem cells. These cells live in the bone marrow and give rise to all the different types of blood cells. This process can go awry and lead to deadly disorders like leukemia, so scientists are very interested in exquisitely understanding each step that a blood stem cell takes as it specializes into different cell types.
Researchers can figure out the fate of a blood stem cells by adding tags, which glow with various color, to the cell surface . Under a microscope these colors reveal the cells identity. But this method is always after the fact. There no way to look at a cell and predict what type of cell it is turning into. In this study, the team filmed the cells under a microscope as they transformed into different cell types. The deep learning algorithm processed the patterns in the cells and developed cell fate predictions. Now, compared to the typical method using the glowing tags, the researchers knew the eventual cell fates much sooner. The team lead, Carsten Marr, explained how this new technology could help their research:
“Since we now know which cells will develop in which way, we can isolate them earlier than before and examine how they differ at a molecular level. We want to use this information to understand how the choices are made for particular developmental traits.”
Stem cell therapy for ALS seeking approval in Canada. (Karen Ring) Amyotrophic lateral sclerosis (ALS) is a progressive neuromuscular disease that kills off the nerve cells responsible for controlling muscle movement. Patients with ALS suffer from muscle weakness, difficulty in speaking, and eventually breathing. There is no cure for ALS and the average life expectancy after diagnosis is just 2 – 5 years. But companies are pursuing stem cell-based therapies in clinical trials as promising treatment options.
One company in particular, BrainStorm Cell Therapeutics based in the US and Israel, is testing a mesenchymal stem cell-based therapy called NurOwn in ALS patients in clinical trials. In their Phase 2 trials, they observed clinical improvements in slowing down the rate of disease progression following the stem cell treatment.
In a recent update from our friends at the Signals Blog, BrainStorm has announced that it is seeking regulatory approval of its NurOwn treatment for ALS patients in Canada. They will be working with the Centre for Commercialization of Regenerative Medicine (CCRM) to apply for a special regulatory approval pathway with Health Canada, the Canadian government department responsible for national public health.
In a press release, BrainStorm CEO Chaim Lebovits, highlighted this new partnership and his company’s mission to gain regulatory approval for their ALS treatment:
“We are pleased to partner with CCRM as we continue our efforts to develop and make NurOwn available commercially to patients with ALS as quickly as possible. We look forward to discussing with Health Canada staff the results of our ALS clinical program to date, which we believe shows compelling evidence of safety and efficacy and may qualify for rapid review under Canada’s regulatory guidelines for drugs to treat serious or life-threatening conditions.”
Stacey Johnson who wrote the Signals Blog piece on this story explained that while BrainStorm is not starting a clinical trial for ALS in Canada, there will be significant benefits if its treatment is approved.
“If BrainStorm qualifies for this pathway and its market authorization request is successful, it is possible that NurOwn could be available for patients in Canada by early 2018. True access to improved treatments for Canadian ALS patients would be a great outcome and something we are all hoping for.”
CIRM is also funding stem cell-based therapies in clinical trials for ALS. Just yesterday our Board awarded Cedars-Sinai $6.15 million dollars to conduct a Phase 1 trial for ALS patients that will use “cells called astrocytes that have been specially re-engineered to secrete proteins that can help repair and replace the cells damaged by the disease.” You can read more about this new trial in our latest news release.